Your advice please regarding long term storage of Omega Seamaster

If it's going to sit unused for many years, no amount of 'exercise' or winders will get over the fact that a service would be recommended before it's worn regularly.

I'd be more concerned with keeping it somewhere that's reasonably dry.

Are you going to prison or is it a birthdate gift etc?

Seemingly is the key word. If you are concerned about preventing damage, then don't wind it again until you get that one serviced. By running it in it's current state now you will cause damage.

Oils will deteriorate regardless if the watch is being used or not. Most oils simply dry up, so nothing but a slight residue is left behind - this is what dry oil on the underside of a jewel looks like:



As your experience has just shown, movements will not typically become "seized solid" after sitting for a number of years. Some older natural oils will get very tacky, and could possibly cause a watch not to run, but that isn't anything that can't be resolved by a service. There is no need to run the movement at all if your intent is to let the watch sit in a safe - oils are held in place by capillary action and will not migrate away. They just dry up, so as long as whoever uses these watches in the future gets them serviced before they are used, they should be fine.

Cheers, Al